When constructing data processing or communication equipment, it is generally desirable to emulate the operation of various components and the interaction of these components with each other before all such components are available for actual physical testing. Such emulation generally enables the identification of potential fault conditions to be identified and the exercise of software within host devices designed to identify and respond to fault conditions originating within peripherals or other devices.
Generally, prior art systems are able to emulate data communication between the host and its peripheral devices occurring under steady state conditions. This may be accomplished by connecting data communication wiring or cabling between the host and emulator and causing the host equipment to communicate with the emulating device or emulator. Generally, the emulator is intended to operate, from the vantage point of the host device, just as though it were the device being emulated. The emulator generally emulates operation of a selected device under conditions wherein control signal conditions and power connections to the device being emulated are fixed throughout an emulation session.
FIG. 1 depicts an apparatus for conducting emulation of a peripheral device according to a prior art solution. Host device or host computer 101 is shown connected to emulator 102 by data connection 103. Any variation in the control settings and power settings of a device being emulated by emulator 102 is generally established by emulator 102 itself.
While the prior art solution may effectively emulate operation of the data connection between host computer 101 and emulator 102, the prior art setup of FIG. 1 will generally not allow host computer 101 to respond to variations in control settings and power conditions within emulator 102 as host device 101 will generally have no information pertaining to such control settings and power conditions.
Accordingly, the prior art emulation approach eliminates an entire category of testing of apparatus 100. For example, any effects of power-up or power-down operations within emulator 102 will generally not be discernible to host computer 101. Accordingly, host computer 101 will generally not be able to determine how fault detection and recovery software, which may be present in host computer 101, would respond to such power cycling operations.
Accordingly, it is a problem in the art that emulation generally does not enable host devices to determine or measure control settings and power conditions present in an emulator.
It is a further problem in the art that if a change in a control setting or power condition for an emulated device causes a disruption in data communication, the host computer will generally not be able to determine a cause of such disruption.
It is a further problem in the art that host device fault detection and recovery software will generally not be fully exercised in prior art emulation systems.